Cigarettes are commonly sold in hinge-lid cardboard packs having a box portion and a lid portion, which is hinged to the rear wall of the box portion. In use, with the pack in an upright position, the front of the lid portion is pivoted up and to the rear by the consumer to open the pack and thereby allow access to a bundle of cigarettes standing in the box portion. When the lid portion is closed, the front, side and rear walls of the lid portion form vertical extensions of the corresponding walls of the box portion.
Hinge-lid cigarette packs normally also include an inner frame or collar mounted inside the front and sides of the box portion, at least a portion of which projects from the box portion into the space covered by the lid portion in the closed position. A central cut-out is provided in the front wall of the inner frame to allow the consumer to readily remove cigarettes from the hinge-lid pack in the open position. In use, the inner frame provides interference or frictional engagement with the lid portion as it opens and closes, thereby helping to prevent accidental opening of the pack and helping to retain the lid portion in the closed position when desired. In addition, the inner frame also serves to reinforce the box portion of the hinge-lid pack.
Typically, the box portion and the lid portion of the hinge-lid cigarette pack are formed from a single, folded, laminar cardboard blank and the inner frame is formed from a second, separate, laminar cardboard blank. To produce the pack, a bundle of cigarettes wrapped in, for example, metallised paper or aluminium foil is placed together with the second laminar cardboard blank in a pocket on a wrapping wheel, which is lined with the first laminar cardboard blank. The wrapping wheel is indexable between a number of stations and as the pocket indexes around from station to station, the first laminar cardboard blank is folded in stages around the wrapped bundle of cigarettes and inner frame to form the hinge-lid pack. Typically, the formed hinge-lid cigarette pack is then shrink wrapped or otherwise over wrapped with a transparent polymeric film of, for example, polyethylene or polypropylene.
Hinge-lid containers with an integral inner frame, which are formed from a single, folded, laminar cardboard blank are also known. The blanks for such containers can be complicated and, in order to erect the container, require reverse folding that is difficult to achieve using conventional machinery.
Laminar cardboard blanks from which hinge-lid cigarette packs and other hinge-lid containers are formed often include an inner lid panel that extends from the panel of the blank which, in use, forms the front wall of the lid portion of the pack. During production, this inner lid panel is folded through 180 degrees and affixed to the inner surface of the lid front wall panel of the blank so that in the formed hinge-lid container it rests against the inside of the front wall of the lid portion thereof. As well as providing reinforcement to the lid portion of the formed hinge-lid container, the inner lid panel may be provided with retention means that, in use, cooperate with portions of an inner frame mounted in the container to retain the lid portion thereof in a completely closed position, with the lower edges of the lid portion abutting the upper edges of the box portion. In addition, the outer surface of the inner lid panel may be advantageously printed with consumer information. The fold line formed between the inner lid panel and the lid front wall panel also advantageously provides a neat, dull lower front edge to the lid portion of the formed hinge-lid container.
In spite of the benefits discussed in the preceding paragraph, the inclusion of an inner lid flap in hinge-lid cigarette packs and other hinge-lid containers disadvantageously results in the lower region of the front wall of the lid portion of the container being of increased thickness compared to the upper region of the front wall of the box portion thereof. Due to the presence of the reinforcing flap, the bottom edge of the front wall of the lid portion is twice the thickness of the top edge of the front wall of the box portion against which it abuts when in the closed position. Such a thickness differential across the lid line is undesirable as the misalignment between the front wall of the lid portion and the front wall of the box portion can give rise to creases or wrinkles in polymeric film over wrappers subsequently applied to the formed hinge-lid container; as well as being unsightly, creases or wrinkles formed in the polymeric film may interfere with subsequent manufacturing and transport operations involving the over wrapped hinge-lid container.